Post by jackbcryan on Sept 14, 2011 14:30:31 GMT -5
I am trying to identify this water meter for a building built in 1992. Trying to locate the flow range for this meter so I can replace it with a new one of similar flow range. Appreciate the help. Jack
Post by Meter Repair on Sept 14, 2011 16:18:52 GMT -5
thats a 3 inch turbine meter. what is its application? or what will you be supplying with water? turbine meters are designed for consistant flow of water, they dont do well at low flow ranges. i work with neptune meters every day as part on my job.
heres some ways which meters can be used.
commercial irrigation (best use for a turbine) commercial supply for manufacturing small commercial shops for bathrooms and sinks residential apartment complex residential single residence
let me know and i can figure out the best meter for your application or provide you with more info on your 3 inch turbine.
Post by jackbcryan on Sept 15, 2011 11:30:22 GMT -5
Hi John, thanks for the feedback. This is a 7000 sq m commercial building with a pub and a cafeteria inside. So there is a kitchen as well. It also holds an office area of about 30 staff. There's a conference hall with capacity for 1000. Just wondering if replacing it with a Sensus 3" SRH compound meter rated for flow between 0.5 to 320 gpm will be a good idea. What's the flow range for this Neptune by the way? Thanks.
Post by Meter Repair on Sept 15, 2011 22:21:26 GMT -5
i have requested some info on the older Neptune turbine series from Neptune, i didn't have any detailed info on it in my shop.
if you are wanting to have accurate billing for this address, a compound will be the way to go.
a compound is made up of 2 sections, using a 3" neptune tru/flo as an example, the 1st section is a small chamber, the small chamber in the 3 in tru/flo is the standard residential T-10 5/8 meter measuring chamber. from my testing on the shop test bench, this 5/8 chamber can measure flows down to .08 gpm. in the 3" tru/flo the 5/8 register reads flow from that point up to the changeover to the main turbine. the changeover is around 10 gpm. at changeover, the flow thru the 5/8 chamber is reduced and maintained around 10 gpm so as to not damage it from being over driven.
the 3 inch turbine you have, will not reliably measure flows much below 4-5 gpm, tho flows as low as 1-2 gpm may inch the turbine along sporadically.
i have the spec sheet on the Sensus SRH compound. i will post pictures of the sheets in another thread and then put a link to it in this thread.
i have noticed that it only has 1 register, it concerns me that if the small measuring chamber stops or fails, you wouldnt know it. i suspect the dial would continue to move for larger flows thru the mainline turbine.
with the Neptune tru/flo it has separate registers so you can quickly identify a stopped chamber or turbine needing repair.
also, sensus uses piston type chambers for the small section. we have alot of older 5/8 Rockwell meters in our city which use piston chambers. there is alot more surface area to drag when water is moving thru the chamber and as a result, low flow accuracy is compromised when chambers start wearing. i have personally tested many rockwell piston meters on our shop test bench, and its not uncommon to have older chambers not move until 1-2 gpm of flow. some are bad enough that they wont even show a constant leak on a toilet. we are actively working on replacing ALL of these piston type meters with neptune T-10DC series backflow meters.
neptune tru/flo uses nutating discs for the small chamber, which have much less surface area to drag, and i usually see noticabally higher accuracy of old 5/8 residential neptune nutating disc meters. many are still around 95% at .25 GPM test rate even with over a million gallons
depending on flow demand you may get along fine with a 2 inch compound. we have 2 inch meters on several trailer parks with at least 100 trailers and it is sufficient. from the sounds of it you arent going to have consistent high flow, i would figure no more than 50-75gpm under most circumstances. i would say that peak might be if alot of toilets get flushed at once.
Post by jackbcryan on Sept 16, 2011 14:47:55 GMT -5
Thanks John. I feel sure this 3" Sensus compound SRH will do the job. It's just that the as-built for the building indicated water usage of 227 liter/second. Which translates to 3600 gpm. Which I thought is nonsensical. So I think its a typo. That's why I wanted to veriy the flow range of the original Neptune 3" Turbine. Jack.